\begin{tabular}{@{}l!{\quad}S[table-format = 2.3,table-space-text-post={*}]!{\quad}S[table-format = 2.3,table-space-text-post={*}]!{\quad}S[table-format = 2.3,table-space-text-post={*}]!{\quad}S[table-format = 2.3,table-space-text-post={*}]!{\quad}S[table-format = 2.3,table-space-text-post={*}]!{\quad}S[table-format = 2.3,table-space-text-post={*}]!{\quad}@{}}%
\toprule%
&\multicolumn{1}{c}{Low Pred.}&\multicolumn{1}{c}{2}&\multicolumn{1}{c}{3}&\multicolumn{1}{c}{4}&\multicolumn{1}{c}{High Pred.}&\multicolumn{1}{c}{H{-}L}\\%
\midrule%
\multicolumn{7}{c}{Stock Arbitrage Score}\\%
\midrule%
Low&{-}0.650***&{-}0.273**&{-}0.168&{-}0.092&0.103&0.754***\\%
2&{-}0.891***&{-}0.335**&{-}0.199&{-}0.082&0.221&1.112***\\%
3&{-}1.125***&{-}0.402***&{-}0.190&{-}0.080&0.349&1.474***\\%
4&{-}1.371***&{-}0.436***&{-}0.191&0.043&0.592**&1.963***\\%
High&{-}2.529***&{-}0.857***&{-}0.313*&0.062&0.813***&3.342***\\%
H{-}L&{-}1.878***&{-}0.584***&{-}0.145**&0.154**&0.710***&2.588***\\%
\midrule%
&&&&&&\\%
\multicolumn{7}{c}{Option Arbitrage Score}\\%
\midrule%
Low&{-}1.105***&{-}0.316**&{-}0.142&{-}0.023&0.275&1.380***\\%
2&{-}1.214***&{-}0.266*&{-}0.076&0.038&0.399**&1.613***\\%
3&{-}1.249***&{-}0.276**&{-}0.049&0.089&0.483**&1.732***\\%
4&{-}1.388***&{-}0.293**&{-}0.037&0.122&0.615***&2.003***\\%
High&{-}1.487***&{-}0.362***&{-}0.073&0.188&0.767***&2.255***\\%
H{-}L&{-}0.382***&{-}0.046&0.069&0.211***&0.492***&0.874***\\\bottomrule%
%
\end{tabular}